JPS593145B2 - Heihan Insatsubanno Seizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a lithographic printing plate, and the object thereof is to provide a plate-making method that allows plate-making to be performed quickly and easily, and also enables lithographic printing without using any dampening water or the like. It is on offer.

Recently, compact offset printing machines for office use have been widely used as a means for high-speed, especially large-scale copying, due to their low copying cost, speed, and good finish.

However, in normal offset printing, so-called dampening water is used to moisten the non-image area of the plate surface and retain water, making the non-image area non-receptive to ink.On the other hand, hydrophobic and lipophilic image areas are This method uses the principle that when inking is done with an ink roller, the ink adheres only to the printed area because it blends in with the ink.It has various advantages, but requires technical skill because it uses dampening water. In short, when using dampening water, which is characterized by a complex printing machine and considerable technical skill in its operation, too little dampening water will stain the non-print areas, and too much dampening water will cause emulsification of the ink, making it impossible to obtain clean prints. .

Therefore, a so-called water-free planographic printing method has been proposed in which the above-mentioned defects are removed by performing planographic printing without using dampening water.

A typical method is to use silicone.

This takes advantage of the fact that silicone has a strong ability to absorb oil, and instead of moistening non-image areas with water, these areas are covered with silicone.

However, this method has the disadvantage that the printing plate has a multilayer structure, and the manufacturing process is complicated, making it unsuitable for small office offset machines that need to be small and easy to manufacture. .

Under these circumstances, the present inventor has completed the present invention as a result of intensive research into a method for manufacturing a lithographic printing plate that can be made quickly and easily and that can provide excellent printing without using dampening water.

That is, the present invention involves forming desired lines (images) on a suitable base sheet surface using hydrophilic urea-formaldehyde or melamine-formaldehyde initial condensate, and then applying silicone to the sheet surface. In this method, silicone is absorbed or adhered to the non-image areas, and then the whole is heated to cure the initial condensate in the image areas and the silicone in the non-image areas at the same time to obtain a lithographic printing original plate. .

As a result, the imaged areas undergo condensation and harden, becoming hydrophobic and lipophilic, while the silicone in the non-imaged areas hardens and becomes oil-insensitive (oil-repellent).

That is, if the oil-based ink is inked over the entire surface with a roller, the ink will adhere to the image area, but will not adhere to the non-image area due to the heat.

Therefore direct or indirect (use of rubber blanket)
Lithographic printing became possible.

Application of silicone only to the non-image areas can be easily achieved by applying the silicone to the entire surface.

This is because the initial condensate before curing is hydrophilic and has the property of grinding the silicone solution (generally, a solution of silicone in an organic solvent such as an aromatic hydrocarbon is used).

The base sheet used in the present invention may be paper, metal, plastic, glass, etc.

However, plastic is preferable in terms of mechanical strength and flexibility.

The thickness of the base material is not particularly limited, but it is 30 to 500μ for handling purposes.
is preferred.

The condensate of urea or melamine and formaldehyde used to form the streaks needs to be a particularly hydrophilic initial condensate.

It is not acceptable if the condensation stage progresses and hardens, making it insoluble and infusible.

If a streak is formed using a hydrophilic initial condensate, and then silicone is applied over the entire surface as described above: only the streak will be ground, and this streak will become lipophilic after being heated and cured.

The following additives can be added to such an initial condensate in order to improve the mechanical properties within a range that does not impede hydrophobicity, lipophilicity, and oil sensitivity after curing.

Ru.

For example, water-soluble resins such as polyacrylamide, methyl cellulose, gelatin, casein, polyvinyl alcohol hydroxyethyl cellulose, polyvinyl pyrrolidone, carboxymethyl cellulose, polyethylene oxide, and gum arabic are used.

Although the amount varies depending on the type, it usually needs to be 10% by weight or less.

Incidentally, in order to increase the curing speed during curing, 0.1 to 5% by weight of a catalyst can also be used.

For example, in the case of a urea-formaldehyde initial condensate, ammonium salt catalysts such as ammonium chloride, ammonium phosphate, ammonium acetate, ammonium oxalate, and ammonium thiocyanate are used; Ammonium salts such as ammonium, ammonium sulfaminate, dimethylaniline hydrochloride, pyridine hydrochloride,
Organic amine salt-based catalysts such as picoline-monochloroacetic acid, Catalyst AC (manufactured by Monsando), and Catanite A (manufactured by Nitto Kagaku Co., Ltd.), or inorganic metal salt-based catalysts such as magnesium chloride, zinc chloride, and zinc sulfate can be used.

Note that the drawing lines can be formed by hand-drawing, printing, various printing methods, electrostatic photography, and various other known methods as necessary.

The silicone that is applied to the non-image area is a curable type, and is cured by heat treatment using silicone gum as shown in the standard.

R in the above formula is an alkyl group, an allyl group, a halogenated alkyl group, or a halogenated allyl group, which may be the same or different, and n is about 2 to 20,000.

As is generally known, a catalyst is preferably mixed into the polymerizable silicone gum to accelerate curing, and organic carboxylates of tin, zinc or other polyvalent metals are used.

The thickness of the coating film is not particularly limited, but is optimally 0.5 to 20 microns, preferably 1 to 10 microns.

After forming the image area and the non-image area in this way, the heat treatment is usually performed at a temperature range of 50 to 150 DEG C. using a known heating device.

If the thus obtained printing plate of the present invention is directly inked with an ink roller, the ink will be applied only to the image area, and no ink will adhere to the non-image area, and no ink stains will occur even after many printings. The lines remain clear and the lines remain clear.

As described above, the method of the present invention does not use special materials or photosensitive materials, does not require complicated means, and can be made very easily. It is possible to easily obtain a large number of excellent printed materials by maintaining clear non-printing areas and clear printing lines.

Furthermore, in conventional planographic plates that do not require water, unnecessary portions had to be removed by dissolution, but in the present invention, there is no need for elution and plate making can be completed with a simple operation, which is extremely effective.

Example 1 After charging and exposing zinc oxide paper (photoconductive photosensitive paper) using Nirefax manufactured by Iwasaki Tsushinki Co., Ltd., ■ Charged Nikaresin S-26
0 (melamine resin manufactured by Nippon Carbide Industries Co., Ltd.) powder was used for development.

Next, 1 μm of a silicone solution having the following composition was applied, and after drying, the entire surface was heat-treated at 130° C. for 5 minutes.

The planographic plate thus obtained was mounted on a printing cylinder, inked without dampening water, and offset printed, resulting in clear printed matter.

KS705F (30% solution) (Silicone manufactured by Shin-Etsu Chemical Co., Ltd.) 100g Cata
lystPS (tt catalyst) 4g toluene
2009 Example 2 A solution of Formulation A was screen printed on an Al plate as an ink.

Next, a silicone solution of Formulation B was applied (10 μm), dried, and then heated at 150° C. for 2 minutes. The same procedure as in Example 1 was performed to obtain clear printed matter.

Blend U-RAMIN P-1800 A (Mitsui Toatsu urea resin initial condensate) 25g Polyvinyl alcohol 2g Ammonium chloride 0.25g Water
50rrLl combination 5YL-off2
3 (30% solution) B (Silicone manufactured by Toshi Shirilawn Co., Ltd.)
100g5H-23K (catalyst) (catalyst) 5
fl xylene 200g Example 3 An image was drawn with a brush on a frosted polyethylene terephthalate film (100μ) with a solution of Formulation A.

After drying this, apply 3μ of the solution of formulation B and after drying,
When heat treated at ℃ for 5 minutes and operated in the same manner as in Example 1, clear printed matter was obtained.

Formulation A SUMIRE Z RESIN607 (Melamine resin initial condensate manufactured by Sumitomo Chemical Co., Ltd.) 25 g Polyvinylpyrrolidone 2 g Catanite A (Catalyst manufactured by Nitto Chemical Co., Ltd.) 1 g Water 50 m
7 formulation B KE102RTV (Silicone manufactured by Shin-Etsu Silicone Co., Ltd.) 1oogCat
alyst RE (t/catalyst) 0.5p xylene 2009

Claims (1)

[Claims] 1 After forming a desired image area on the base sheet surface with a hydrophilic initial condensate of urea or melamine and formaldehyde, apply silicone to the sheet surface to form a silicone layer on the non-image area, and then A method for producing a lithographic printing plate, which comprises heating and curing both the initial condensate and silicone.